Collapsible wheel chair



May 28, 1957 E. DELON ET AL COLLAPSIBLE. WHEEL CHAIR 5 Sheets-Sheet 1Filed June 2, 1955 ONA o N MAJ P 7 f o m w M wmf v B y 8, 1957 E. DELONETAL 2,793,681

COLLAPSIBLE WHEEL CHAIR Filed June 2, 1955 5 Sheets-Sheet 2:

IN VEN TORS E0 W //V DEL 0N BY Wow-Er JEMARV- A TTOP/VE Y5 y 8, 1957 E.DELON ET AL 2,793,681

COLLAPSIBLE WHEEL CHAIR Filed June 2, 1955 3 Sheets-Sheet 5 UnitedStates Patent COLLAPSIBLE WHEEL CHAIR Application June 2, 1955, SerialNo. 512,695

Claims. (Cl. 155-147) This invention relates to improvements in foldingor collapsible chairs and more particularly to improvements invertically folding, preferably wheeled, collapsible chairs and inlocking or latching mechanisms for automatically and releasably securingsuch chairs in the open position.

It is a general object of this invention to provide an improvedvertically folding collapsible chair which is attractive and pleasing inappearance, strong and light in const-ruction and easily and readilyfolded and unfolded, and which may be safely and expeditiously used.

Other objects include the provision of a vertically folding collapsiblechair which is substantially automatically and positively secured andlocked in the open position when the chair is unfolded, and theprovision of an improved locking or latching mechanism for a verticallyfolding collapsible chair which guides and/or supports the chair seat,which positions the chair when the same is unfolded and locks andsecures the chair in the open position, and which is easily andconveniently released or unlocked when the chair is to be collapsed orfolded but which will not unlock prematurely or unexpectedly even thoughthe chair frame is twisted, rocked or otherwise distorted.

Other objects include the provision of a vertically folding collapsiblewheel chair which may be easily and economically manufactured, which islight, strong and safe, which folds compactly and is easily andconveniently transported, handled and stored as, for example, in anautomobile or in the trunk thereof.

Another object is to provide a locking mechanism for maintaining thewheel chair in the open position that is durable, secure and strong, andwill not prematurely unlock even though the chair be wheeled whenoccupied, over rough and uneven surfaces, curbs or other irregularities,or uneven forces are otherwise imposed on the frame, so that the partsthereof are twisted, strained or racked relative to each other.

These and other objects and advantages of my invention will appear fromthe following description of a preferred embodiment thereof withreference to the appended drawings in which:

Figure 1 is a perspective view of a vertically folding, collapsiblewheel chair embodying a preferred form of our invention as shown in itsopen position.

Figure 2 is a view of the chair shown in Figure 1 when the same iscompletely collapsed or folded.

Figure 3 is a broken perspective view of the chair looking upwardly atthe bottom of the seat and showing the locking mechanism.

Figure 4 is a broken perspective side view of the chair when the same isnearly completely open or unfolded.

Figure 5 is a section taken along the line 5-5 of Figure 3, showing theseat locking mechanism partly in section.

Figure 6 is a top plan view of the seat locking mechanism with the seatremoved therefrom.

The preferred embodiment of our invention as shown in the drawings anddescribed below embraces a vertically folding, collapsible wheel chairalthough certain objects 2,793,681 Patented May .28, 195.7

and aspects of our invention are equally applicable to other types offoldable chairs such as those without wheels.

Referring now to Figures 1 and 2, a vertically folding Wheel chair 2embodying a preferred form of our invention has a frame which isconveniently formed from tubular metal. The chair 2 comprises left andright front legs 4 and 6 respectively and left and right rear or backlegs 8 and 10 respectively. The respective front and back legs, 4 and-8, and 6 and 10 cross each other or intersect X fashion and arepivotally secured together at the point of crossing as by fasteningmembers 12 and 114 respectively. A substantially U-shaped backsupporting member 18 and a transversely extending rearward seatsupporting member 20 interconnect the upper and rearward ends of thefront legs at a convenient height for the seat (when the chair is openor unfolded) and are pivotally secured thereto by pivotal fasteningmembers 22 and 24, Figures =1 and 3.

The lower and forward ends of the front legs are preferablyinterconnected by a rigid brace or crossbar 25 which is convenientlyformed integral with the front legs.

A forward seat supporting crossbar or brace 26, Figure 3, extendsbetween and is secured, as by welding, to the upper forward portions ofthe rear legs 8 and 10 at such a location as will, when the chair isunfolded, support the forward end of the seat at a proper and convenientheight and in proper relation to the height of the rearward seatsupporting member 20.

A rigid seat 28 is secured to the rear seat supporting member 20, as bybolts and nuts 32, for pivotal motion about the pins 2224, and extendsforwardly of and rests upon and is supported by the forward crossbar 26.A locking or latching mechanism indicated generally at 34 andhereinafter more fully described, releasa bly secures the seat 28 to theforward seat supporting crossbar 26 when the chair is unfolded to itsopen operative position as shown in Figure l.

The rear legs 8 and 110 are bent upwardly and inclined rearw-ardly justforward of the cross bar 26 as at 38 and 40 respectively to form thefront posts '42 and 44. The posts 42 and 44 are of sufficient length tosupport the left and right arm rests 46 and 48 at a convenient heightwhen the chair is unfolded. The left and right arm rests 46 and 48extend between the front posts 42 and 44 and the back supporting member18 and are pivotally secured to the front posts 42 and 44 respectivelyand the back supporting member 18 by pivotal fastening members 50 and 52and 54 and 56 respectively.

The lower and rearward ends of the back legs 8 and 10 are preferablyprovided with transversely extending holes through which an axle 62extends. Left and right wheels, 64 and 66 respectively, are mounted onthe axle 62 as shown.

The front legs 4 and 6 are preferably .bent forwardly near their forwardand lower ends as at 70 and 72 respectively so as to extendsubstantially parallel with the floor, and castor type front wheels 74and 75 are secured to these forward portions thereof. The relationshipbetween the size of the front wheels 74 and 75 and the angle andlocation of the bends 70 and 72 is such that when the chair is foldedthe front wheels will extend angularly forwardly .(see Fig. 2) relativeto the rear axle so that the forward end of the chair when folded willnot be substantially higher than the diameter of the rear wheels and thefolded chair will be compact in size and therefore easily handled,transported and stored.

A rigid back 76 is secured to the back supporting mem- 'ber 18, and afootrest 78 is pivotally secured to the lower 7 As will hereinafter morefully appear, the locking mechanism is'adapted on the one hand to safelyand securely lock the chair in the open or unfolded position andpreclude the premature or undesired collapsing thereof even though thechair be lifted by the seat, pushed or wheeled over rough and unevensurfaces, curbs and steps and the frame be thereby unevenly loaded,twisted and racked and on the other hand to be easily and convenientlyunlocked whenever it is desired to collapse and fold the chair.

The locking mechanism, see Figures 3, 4, and 6, includes a downwardlyopening channel member 82, which extends transversely of and is securedto the forward under side of the seat 28 (as suggested by bolts 28ahaving minimum protuberance above the top surface of the seat and withinthe channel) and is adapted to fit over and seat upon the forward seatbrace 26 when the chair is fully and properly opened, means toautomatically position the channel 82 as the chair is opened and meansto releasably lock the channel in seated engagement with and over thebrace 26.

To this end the channel 82 preferably and conveniently has a depthgreater than one half the diameter of brace 26 and a width between itsfront leg 84 and rear leg 86 which is only slightly larger than thediameter of the brace and a length about equal to one half the width ofthe seat 28. Thus when the chair is opened and the channel is seated onand over the seat bar the engagement therebetween is such as to precludethe premature or unwanted raising of the seat relative to the brace 26or release of the locking mechanism or disengagement of the channel andseat bar and/or inadvertent collapsing or folding of the chair.

In order to position the chair and seat properly and to prevent thechannel 82 from being carried forwardly of the brace 26 when the chairis unfolded a flat hook or stop member 90 is secured, as by welding, tothe rearward side of the rear leg 86 of channel 82. The stop 90 extends,preferably in an arc, downwardly and forwardly from the leg 86 so thatits lower edge 94 lies below and forwardly of the leg 86. The stop is ofany convenient width and thickness and of suflicient length to catch andbear upon the brace 26 as will hereinafter more fully appear.

A resilient locking bar 98 is secured, near its right end as viewed inFigure 6, to the forward leg 84 of the channel 82. The locking bar 98lies parallel with and extends longitudinally along the channel leg andhas its left end 100, as viewed in Figure 6, which extends beyond theend of the channel towards the side of the chair, Figures 3 and 6. Thelocking bar is secured to the channel leg 84 near its right end by apair of longitudinally spaced nuts and bolts or rivets 96. The outerportion 100 of the bar conveniently extends almost to the outer edge ofthe seat 28 and is preferably bent slightly forward so that the usermay, when desired or necessary, easily grasp it and pull the left end ofthe bar forwardly against its own resilience Wherewith to unlock thechannel from the brace, as will more fully appear.

A flat curved guide member 108 is secured as by welding to the upperportion of the brace 26, Figures 3, 5 and 6, and extends forwardlyslightly beyond the brace and rearwardly and downwardly behind the bracefor a distance exceeding the relative rearward and downward motion ofthe channel relative to the brace when the chair is entirely folded. Theguide member 108 is adapted to guide the movement of the seat 28 andsupport the seat and channel 82 when the chair is being unfolded .orfolded or is in the ,folded position. To end the front of the forwardend 110 of the guide.

ously the'channel 82 is moved downwardly over the brace member 108 issecured to the brace 26 at a point nearer the side of the chair than theadjacent end of the channel 82 and toward the same side of the chair towhich the end 100 of the locking bar 98 extends. More particularly theseat and channel are supported by the locking bar riding on andsupported by the upper side of the guide 108 when the chair is in otherthan the fully open position, see Figure 4. The guide 108 extends overand forwardly from the brace 26 a distance sufficient to raise thelocking bar 98 and the forward leg 84 of the channel 82 above and overthe brace 26, when the chair is being opened, but a distanceinsufficient to raise stop -92 over the brace. Thus the forward movementof the seat is arrested when the stop 90 engages the brace 26 and thechannel is then positioned above the brace so that a downward movementof the seat brings the channel down to straddle and engage the brace,Figure 5. Meanwhile the sprung end of the locking bar 98 has rested onthe forwardly and downwardly sloping surface of the guide 108 whenceforcible downward movement of the seat and channel springs the end 100of the locking bar over the end of the guide, permitting the channel tocome down on the brace, and the position of the end 100 of the guide isrelated to the upper edge of the locking bar such that the bar springsback under the end of the guide when the channel is home and seated onthe brace, Figure 5. Thus the seat is locked and secured in the openposition and cannot be removed therefrom until the end 100 of thelocking bar is sprung outwardly as suggested in dotted lines at 10011 inFigure 6.

The guide member 108 also extends rearwardly and downwardly from thebrace 26 and is of suflicient length to support the locking bar when thechair is completely folded. The angle at which the guide 108 extends is.

conveniently such as to support the seat in the position shown in Figure2 when the chair is folded. Since the seat is supported on the guide 108by the bar 98 when the chair is folded and since the guide is secured tothe upper part of the brace 26, the seat will always be raised above theseat bar 26 when the chair is unfolded and will not be caught beneaththe seat bar as might otherwise be possible.

In operation and with the chair folded as shown in Figure 2, the seatwill, as previously explained, be supported in the position shown bymeans of the locking bar 98 resting upon the upper side of the guidemember 108. To unfold the chair, the user need merely grasp thehorizontal portion 114 of the back supporting member 18 and raise up onthe same. This in efiect causes the front part of the seat to move in aforwardly and upwardly direction, the front wheels to move in a rearwarddirection, and the brace 26 to move in and upwardly and rearwardlydirection relative to the seat and channel. Thus the motion of the chairseat is forward and that of the brace rearward and their relative motionis toward each other. As the chair unfolds the locking bar 98 rests onand rides upon the guide 108 and when the chair approaches its openedposition the bar 98 will have ridden up the guide to the highest pointthereof thereby lifting the channel 82 up and over the brace 26 andcontinued opening of the chair is indicated by the stop 90 catchingagainst the brace and preventing any further forward movement of theseat and channel relative to the brace. The seat 28 is then moveddownwardly by pressure exerted thereon by the user.

The downward movement of the seat causes the locking bar 98 to movedownwardly and forwardly on and over the upper and forward sloping sideof the forward portion 110 of the guide 108 and as the bar movesdownwardly thereon it is simultaneously displaced forwardly against itsresilient resistance so as to move downward in Simultane- 26. Continueddownward movement of the seat causes the channel to seat upon and overthe brace and moves the top of the locking bar below the lower edge ofthe end 110 of the guide, thereby catching the lock-ing bar beneath theforward end of the guide and securely locking the chair in the openposition.

When it is desired to fold the chair, the end 100 of the locking bar 98is pulled forwardly of the end 110 of the guide and the seat is raisedupwardly until the channel is disengaged from the brace 26. The lockingbar is released and the chair tends to collapse and/or may be foldedfrom the position of Figure 1 to the position of Figure 2 (or ispermitted to fold slowly), the locking bar riding upon the guide 108 andsupporting the seat during and after completion of the folding ashereinbefore described.

Preferably the arms and legs of the chair are so proportioned that thepivot points 54 and 565 may be gently forced slightly beyond center, i.e., beyond lines joining the points 24-52 and 22-50 respectively whenthe chair is fully folded, giving the chair a tendency to stay folded inthe position shown in Figure 2 until a mild but measurable opening forceis exerted thereupon. Resilient contact between the bar 98 and the guide108 remote from the brace 26 when the chair is in its folded position,Figure 2, tends to stress and hold the chair in its overcenter foldedposition.

While we have illustrated and described a preferred form and embodimentof our invention, changes, modifications and improvements thereto willoccur to those skilled in the art and therefore we do not desire to belimited in the scope of our patent to the specific and illustrativedisclosure hereof nor in any manner inconsistent with the progress bywhich our invention has promoted the art.

We claim:

1. In a foldable chair adapted for vertical folding motion comprisingleft and right front and rear legs, each said front leg being pivotallyconnected to an adjacent rear leg at a point remote from theirrespective ends, a seat pivotally secured to and interconnecting saidfront legs above said pivotal connections with said rear legs, a seatbar or brace secured to and interconnecting said rear legs above saidpivotal connections with said front legs and adapted to support saidseat when said chair is unfolded, and having a locking mechanism forreleasably securing said chair in the unfolded position and guiding saidseat during the folding and unfolding of said chair, the improvementwherein said locking mechanism comprises a downwardly opening channelhaving front and rear legs secured to the forward under side of saidseat and extending transversely thereof and having a length less thanthe width of said seat and being adapted to engage said seat bar, a stopmember secured to the rear leg of said channel and extending downwardlyand forwardly therefrom, a locking bar secured to the front leg of saidchannel and extending parallel therewith and extending nearer one edgeof said seat than the adjacent end of said channel, means resilientlyurging said locking bar against the front leg of said channel, and aguide member secured to the upper and rearward portion of said seat barbetween the end of the locking bar and the adjacent end of the channel,said guide bar having a rearward portion extending downwardly andrearwardly from said seat bar and a forward portion extending downwardlyand forwardly from said seat bar, said guide member being adapted tosupport and guide said locking bar while said chair is being folded andunfolded and to retain said locking bar when said channel is seated oversaid seat bar.

2. In a foldable chair adapted for vertical folding motion comprisingleft and right front and rear legs, each said front leg being pivotallyconnected to the adjacent rear leg at a point remote from theirrespective ends, a seat adapted to pivot about an axis between the upperends of said front legs above said pivotal connections with said frontlegs, a brace interconnecting said rear legs and adapted to support saidseat when said chair is in the unfolded position, and having a lockingmechanism for releasably securing said chair in the open position andguiding said seat during the folding and unfolding of said chair, theimprovement wherein said locking mechanism comprises means secured tothe forward under side of said seat and adapted to engage said brace,stop means adapted to limit the forward travel of said means relative tosaid brace when said chair is unfolded; guide means for supporting andguiding said seat when said chair is folded and being unfolded, andlocking means for releasably securing said means for engaging said bracein engagement with said brace when said chair is completely unfolded.

3. The chair locking mechanism according to claim 2 in which said braceengagement means comprises a downwardly opening channel extendingtransversely of said seat.

4. The chair locking mechanism according to claim 2 in which saidlocking means includes catch means secured to said brace and latch meanscarried by said seat and adapted to releasably engage said catch whensaid chair is secured in the open position and to slidably engage saidguide means and support said seat when said chair is being folded andunfolded.

5. Locking mechanism for a folding chair having a seat and a cross barin which a connection between the seat and a cross bar retains the chairinopen position and folding the chair involves rearward sliding motionbetween the seat and the cross bar, said mechanism comprising a U-shapedmember carried by the seat and receptive of the cross bar when the chairis in open position, a guide element spaced from the U-shaped elementand overlying the bar and extending downwardly, rearwardly and forwardlytherefrom, and a resilient locking bar having an end fixedly associatedwith the seat remote from said guide element and adapted to ride on saidguide element and snap over and be caught under the forward end of saidguide element when said cross bar enters said U-shaped element.

References Cited in the file of this patent UNITED STATES PATENTS Re.1,623 Dann Feb. 23, 1864 635,486 Ihde Oct. 24, 1899 1,581,020 RussellApr. 13, 1926 2,383,039 Bushnell Aug. 21, 1945 2,615,725 Person Oct. 28,1952

